/* * Copyright 2017 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.google.firebase.database.integration; import com.google.firebase.FirebaseApp; import com.google.firebase.FirebaseOptions; import com.google.firebase.database.DataSnapshot; import com.google.firebase.database.DatabaseError; import com.google.firebase.database.DatabaseReference; import com.google.firebase.database.FirebaseDatabase; import com.google.firebase.database.ValueEventListener; import java.util.concurrent.Semaphore; public class ShutdownExample { public static void main(String[] args) { final Semaphore shutdownLatch = new Semaphore(0); FirebaseApp app = FirebaseApp.initializeApp( new FirebaseOptions.Builder() .setDatabaseUrl("https://admin-java-sdk.firebaseio.com") .build()); FirebaseDatabase db = FirebaseDatabase.getInstance(app); DatabaseReference ref = db.getReference(); ValueEventListener listener = ref.child("shutdown") .addValueEventListener( new ValueEventListener() { @Override public void onDataChange(DataSnapshot snapshot) { Boolean shouldShutdown = snapshot.getValue(Boolean.class); if (shouldShutdown != null && shouldShutdown) { System.out.println("Should shut down"); shutdownLatch.release(1); } else { System.out.println("Not shutting down: " + shouldShutdown); } } @Override public void onCancelled(DatabaseError error) { System.err.println("Shouldn't happen"); } }); try { // Keeps us running until we receive the notification to shut down shutdownLatch.acquire(1); ref.child("shutdown").removeEventListener(listener); db.goOffline(); System.out.println("Done, should exit"); } catch (InterruptedException e) { throw new RuntimeException(e); } } }